Sealing a piston

[rodbuilder]

I am new to this and was asked about building a small piston to withstand high pressure (1500psi and less). How do you seal a piston against a wall that will need to maintain pressure for a certain amount of time?

 

[kf2qd]

What is it pressurizing? Hydraulic, air?

 

[Bernd]

I am new to this and was asked about building a small piston to withstand high pressure (1500psi and less). How do you seal a piston against a wall that will need to maintain pressure for a certain amount of time?

I didn't know that our small steam/air engines ran at such high pressures? ???

Bernd

 

[rodbuilder]

This is not a model engine but just trying to help out a friend who has a plan for a robot and wants to use a micro air cylinder instead of hydraulics on a part of it.

 

[Brian Rupnow]

Go to any major hydraulics supplier and ask. They have engineers who will recommend seals, materials, bore finishes, all of the info. you require. It is in their own interest to do this, as they hope to sell you the seals.

 

[rickharris]

Depending on the application perhaps Air muscles will do the job. they are quite easy to make you don't need to buy.

http://www.shadowrobot.com/

If you make use a bike inner tube - it's more flexible. Suitable end caps should be turned aluminium works well.

 

[rodbuilder]

thanks, guys the problem is he has hydraulics but no air source and does not want to put in a pump. Brian I will check around and see what I come up with.

 

[BobWarfield]

Rick, the Shadow Robots stuff is really cool!

BW

 

[Mcgyver]

just use an O ring. hydraulic cylinders are are all sealed with soft materials - the pressure by itself isn't the problem, its pressure + area, so you have to keep the gap between cylinder and piston small and it will be fine....and lap the bore smooth the o ring doesn't get chewed up.